Ive read they can be awesome. But not many use it..and the ones who do dont push them hard at all so we really dont have any great references. Hopefully someone else will chime in ive always been curious too

There was a yellow one a few years back that tried to max it out. He made 432 on 32+ psi spiking and falling to whatever on 110 octane. He made 399 whp on 27 psi. Comparing those results to any OTS big turbo...and yeah. I know the Hahn kit guys will be in here down my throat; but ask any of them to produce their numbers and it's easy to see that this turbo chokes hard just to make a little over 400 whp

I agree, find something a little better. Not that theres anything wrong with the hanh 20g turbo kits, let alone the hahn 25g kit rocks, but there are better upgrade turbo options out there to suite your needs imo. But, i made 500+ on my evo9 turbo that i thru in a 20g compressor wheel but i also changed out the stock td05hr turbine for the larger 61mm td06sl2r turbine wheel. I also run on 4bars, e85, and boost 35psi and i have ported everything, ivery supporting mod you can think of, and my turbo setup is more along the lines flowing similar to a hta fpgreen/ef2 from maperformance. About a 54lbs+/minutes turbo. I also have a 38mm external wastegate setup and on a stage3 manifold bored out to fit the larger turbine as well as its porter and polished and on a full 3.5in exhaust system from the 02 housing down. Pretty good turbo setup, but its a completely different setup comparing to your typical hahn 20g kit.

Is the Hahn an outdated turbo yes, will it still make you 400hp yes with the correct mods. One thing you also have to look at is dependability this turbo is made by Mitsubishi so it is made to last. I had good luck with my 16G that I had from Hahn but wanted some more so I sent my turbo in to have the 20G upgrade done but I had them install a 10blade billet wheel that I had gotten through Snail Turbo to see if It couldn't help the out dated turbo out on power. Good luck with your choice